How to set a static transform with our interactive RVIZ tool

How to set a static transform with our interactive RVIZ tool

Sometimes, there is a need to quickly set up a static transform in ROS. To avoid manually searching for translation and rotation parameters, we have written this minimalistic tool that allows us to do it a more convenient, click-and-drag way.

The Problem

The physical configuration of a robot can change or a new sensor is added. Since this configuration is reflected by the ROS TF system, the corresponding static transform needs to be updated. The classical approach would be trial-and-error with the comand line rosrun tf static_transform_publisher [params], looking for the right numbers. It is tedious, unnecessary and there is a better way to do this.

Solution - Interactive Static Transform tool

Following the RVIZ Interactive Marker Tutorial, a simple tool was written. It helps in finding a transformation between two TF frames by providing an RVIZ interactive marker. Its usage is straightforward:

  1. Set your parent and child frame names in the launch file.
  2. Run the launch file and also open the RVIZ.
  3. The initial transformation is an identity, but you can modify it by displaying the interactive marker and moving it around.
  4. The marker also offers a context menu, the only command which is there prints the current transform value in the form of the static_transform_publisher rosrun command.

The launch file and the code is placed within the norlab_imu_tools package:

  <node pkg="norlab_imu_tools" type="" name="interactive_static_transform_publisher_node" output="screen">
    <param name="child_frame" value="moving_frame" />
    <param name="parent_frame" value="base_link" />
    <param name="tf_publish_period_in_sec" value="0.1" />

The final transform output can be copied and pasted into a terminal or just used to set a new launch file:

[INFO] [1556661102.899894]: The equivalent static transform command:
[INFO] [1556661102.902316]: rosrun tf static_transform_publisher 1.92549085617 0.0 1.12673556805 0.327530413866 -0.155546739697 -0.399795621634 0.841839015484 base_link moving_frame 100